Early-onset hay fever in Israeli children

Pediatric allergy and immunology in Israel

After the geographic and sociodemographic settings as well as the health care in Israel are briefly described, the scope of pediatric allergy and immunology in Israel is presented. This includes specific disorders commonly encountered, the environment that induces symptoms, the specialists who treat them, and the common challenges of patients, parents, doctors, and allied health personnel who collaborate to manage the maladies and patient care. Allergies usually affect some overall 15-20% of the pediatric population. The main allergens are inhaled, ingested, or injected (insects stings). Generally, the incidence of the various allergens affecting children in Israel, is similar to other parts of the Western world. Owing to the high consanguinity rate in the Israeli population, the prevalence of the various immunodeficiency conditions (in the adaptive as well as the innate system) is higher than that reported worldwide. Pediatric allergists/immunologists also treat autoimmune disorders affecting the pediatric group. Pediatric allergy and clinical immunology are not separate specialties. The 25 specialists who treat children with allergic/immunologic diseases have undergone a basic training in Pediatrics. They also received an additional 2-yr training in allergy and clinical immunology and then have to pass the board examinations. They work mainly in pediatric allergy units, in several hospitals that are affiliated to the five medical schools in the country. Aside from clinical work, most of the centers are also heavily involved in clinical and basic research in allergy and immunology.

Evidence for the transmissibility of atopy: hypothesis

The etiology of atopy is unknown. Its family distribution suggests transmissibility. Populations moving from countries with a low incidence to those with a high incidence increase to the higher rate. African and New Guinea village groups developed asthma with return of individuals who have acquired atopy in the city. Protection (and possibly immunity) develops with early exposure to child care or to affected older siblings. T helper (Th) type 2 clones driving specific allergies remain active even without further allergen exposure. Other IgE responses remain normal. Once boosted to completeness, the patterns of skin test results remain quite stable, possibly by the localization of abnormality maintained by immunity. An example of a virus causing the immortality of Th2 cells is herpes simplex virus type 1. It infects mouse or human Th2 cells and, although it does not multiply, causes immortality by increasing FAS-mediated apoptosis of T cells directed against the infected cells. Human T-cell leukemia virus 1 and probably others use similar ploys. Abnormal levels of FAS receptors and resistance to FAS apoptosis in nasal polyp lymphocytes and abnormal Th2 clones of atopy are interesting in this regard. The localizing role of a staphylococcal superantigen in atopic dermatitis, and possibly in autoimmunity in nonatopic eczema and intrinsic asthma, encourage the consideration of roles for microorganisms in localization and etiology. The epidemiology and characteristics of atopic disease support the plausibility of a viral hypothesis.

Comparison of positive allergy skin tests among asthmatic children from rural and urban areas living within small geographic area

BACKGROUND

Evidence of increased asthma and allergic response among urban versus rural residents has been reported.

OBJECTIVE

To evaluate the prevalence of allergic response among asthmatic children from urban and rural areas living within close proximity.

METHODS

In all, 448 asthmatic children from urban (363) and rural (85) areas were studied. The study group consisted of 234 9-year-olds and 214 12-year-olds. A health questionnaire was completed on each child who subsequently underwent allergic skin prick tests (SPTs).

RESULTS

There was significantly more positive SPT response to house-dust mite, mold, cat, and cypress among asthmatic children from urban areas compared with children living in rural areas: 58.3% versus 37.6%, 46.1% versus 31.8%, 17.45 versus 5.9%, and 26.2% versus 15.3%, respectively. Positive SPT for indoor allergens were significantly greater among asthmatic urban residents than asthmatic rural residents: 63.3% versus 45.5%, respectively (P < 0.02). Positive SPT response to all the allergens checked was higher among the 12-year-old age group when compared with the 9-year-olds, 34.6% versus 22.7%, respectively (P = 0.05).

CONCLUSIONS

Allergic response measured by SPT is significantly more common among asthmatic children from urban areas as opposed to rural, even though both areas are within small distance of one another. Further, asthmatic children living in urban areas demonstrated more allergic response to both indoor and outdoor allergens. The allergic response tends to increase with increased age in both urban and rural asthmatic children.

The prevalence of allergic rhinosinusitis: a review

A review of the literature indicates that there is an increase in the prevalence of self-reported symptoms suggestive of seasonal allergic rhinitis over the last 70 years. The reason for this remains unclear. Epidemiological studies which relate to the effect of pollution suggest that while pollution can exacerbate respiratory tract symptoms, there is no consistent evidence that high levels result in an increase in the prevalence of allergic rhinitis. The increased prevalence of house-dust mite, an alteration in immunity--possibly related to the number of childhood respiratory tract infections, and increased disease awareness, are all factors which may influence the reported prevalence of allergic rhinitis. At present the inconsistencies which exist in the literature mean that it is possible to 'pick' publications which support one view and ignore the rest, so that a variety of views may be held, each with apparently well referenced endorsement. The criteria defined by Bradford Hill (1965) to establish causation and not mere association between any of these factors and allergic rhinitis have, as yet, not been met (see Table V).

Prevalence of atopic disease among Danish school children

As a result of a 1990 survey by questionnaire, the symptoms of atopy among all 4,952 school children aged 5 to 16 years in the municipal district of Viborg, Denmark, were registered. Random checks, made among children who were recorded as having symptoms, and others who were recorded as having none, accorded well with the information supplied by the parents about symptoms and the clinical diagnosis of a specialist; 10.5% of all school children had rhinitis, 7% had atopic eczema, 3.2% had urticaria and 4.5% had asthma; 1/4 of all those questioned had shown symptoms within the last year, and a further 13% of all the children were reported as having had atopic symptoms that had disappeared more than a year previously. Of the children showing symptoms within the last year before the survey, 2/3 had gone to a doctor. Of the children with present symptoms, largely asthma, 1/4 had been referred to a hospital allergy clinic. For 1/3 of the children with present symptoms, these had led to no contact with a doctor. Of the cases with present symptoms, 6.5% had had contact with natural healers or chiropractors. Rhinitis and asthma were most frequent among boys, while atopic eczema was most frequent among girls. For both sexes, the frequency of rhinitis increased during their years at school, while the frequency of skin symptoms fell.